Swine flu cases in the United States rose above 60 on Tuesday as governments around the world intensified steps to battle the outbreak that has killed scores of people in Mexico.

President Barack Obama asked Congress for $1.5 billion to fight the fast-spreading disease as health officials warned that deaths were likely.

In Toronto, meanwhile, Canadian health officials confirmed a total of 13 cases of swine flu and warned against unnecessary travel to Mexico. The EU's disease control agency as well as Israel and France warned against nonessential travel to Mexico, while Cuba suspended flights to and from Mexico.

U.S. officials suggested the flu may be spreading so fast, there may be no practical way to contain it _ and no need to tighten borders further.

At least seven people have been hospitalized with swine flu in the United States, and Richard Besser, acting director of the federal Centers for Disease Control and Prevention in Atlanta, said deaths are likely.

"I fully expect we will see deaths from this infection" as cases are investigated, he said.

The hospitalizations include three in California and two in Texas, Besser said. Later, New York said two people had been hospitalized.

Besser said the country has 64 confirmed cases across five states, with 45 in New York, one in Ohio, two in Kansas, six in Texas and 10 in California. At least four other cases have been reported by states.

Based on the latest lab analysis, Besser said new flu infections are still occurring.

He noted, by comparison, that ordinary human flu accounts for about 36,000 deaths every year in the U.S.

As health officials moved to try to slow the spread of the new virus, U.S. agriculture officials suggested it would be a good idea to change its name.

The problem, they said, was that the name "swine flu" suggests a problem with pork products.

Agriculture Secretary Tom Vilsack points out that the virus is not food-borne and has nothing to do with consuming pork products. Vilsack says he's concerned that misunderstandings could have a negative impact on farmers who provide pork products to consumers around the world.

The disease has been called swine flu because the underlying virus contains genetic material from swine; but it also contains genetic material from birds and humans, scientists say.

In hard-hit New York, city officials said several hundred students have fallen ill at the New York school hit by a swine flu outbreak.

City Health Commissioner Thomas Frieden said "many hundreds" of schoolchildren are sick with suspected cases of swine flu.

The initial concentration was at a Catholic school in Queens where students recently went on a spring break trip to Mexico. But on Tuesday there were indications that the outbreak may have spread beyond the school, with two people having to be hospitalized and officials closing a school for autistic kids down the road. Those cases have not been confirmed.

"It is here and it is spreading," Frieden said. "We do not know whether it will continue to spread."

Mayor Michael Bloomberg said that 82 of 380 students at P.S. 177, a school for autistic children, have called in sick. A third school in Manhattan is being evaluated because students there are sick, Frieden said.

Across the country, the Los Angeles County coroner's office was investigating the recent deaths of two men, 33 and 45 years old, for links to swine flu. Coroner's Capt. John Kades said the bodies were being tested but that there has been no confirmation the disease killed them.

Gov. Arnold Schwarzenegger has declared a state of emergency in California, which borders Mexico, to help state agencies coordinate efforts in response to the outbreak of the illness.

In Mexico, more than 150 deaths were believed to have been caused by swine flu. There haven't been any confirmed swine flu deaths in the United States.

As Obama requested additional money from Congress to build drug stockpiles and monitor future cases, other U.S. officials suggested the flu may be spreading so fast that stepped-up border security may not help.

She reiterated Obama's statement on Monday as he grappled with the first domestic emergency of his presidency _ that the spread of the disease is a cause for concern but not alarm.

Asked about stricter measures, Napolitano said, "That's something that always can be considered, but you have to look at what the costs of that are. We literally have thousands of trucks and lots of commerce that cross that border. We have food products and other things that have to go across that border.

"So there's a _ that would be a very, very heavy cost for _ as the epidemiologists tell us _ would be marginal, if any, utility in terms of actually preventing the spread of the virus."

Meanwhile, U.S. scientists working on a swine flu vaccine hoped to have a key ingredient ready in early May, but were finding that the virus grows slowly in eggs _ the chief way flu vaccines are made.

Even if all goes well, it still will take a few months before any shots are available for the first required safety testing, in volunteers.

"We're working together at 100 miles an hour to get material that will be useful," Dr. Jesse Goodman, who oversees the Food and Drug Administration's swine flu work, told The Associated Press.